<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>表单</title>
    <link href="css/bootstrap.min.css" rel="stylesheet"/>
    <script src="js/jquery-3.3.1.min.js"></script>
    <script src="js/bootstrap.min.js"></script>
    <style>
        form{
            width: 600px;
        }
    </style>
</head>
<body>
<form method="post" action="#" class="form-horizontal">
    <div class="form-group">
        <label for="username" class="col-lg-3">用户名：</label>
        <div class="col-lg-9">
            <input type="text" name="username" id="username" maxlength="20" class="form-control"/>
        </div>

    </div>
    <div class="form-group">
        <label for="pd" class="col-lg-3">密码：</label>
        <div class="col-lg-9">
            <input type="password" name="password" id="pd" maxlength="20" class="form-control" />
        </div>

    </div>
</form>
</body>
</html>